This Research Project is designed to test whether it is feasible to increase tumor doses over those achievable with traditional radiotherapy techniques, and whether this approach will affect the rates of local control in human primary tumors. We hypothesize that improved local tumor control in patients who have not developed micrometastatic spread at the time of initial diagnosis will result in decreased rates of subsequent metastatic disease and increased survival. Data in the literature generally support this hypothesis indicating that metastatic disease is more prevalent in patients who fail to achieve local primary tumor control, and that the development of metastases may occur secondary to the re-growth of the primary tumor. However, more definitive observations are not available. this Project is the initial step in a long range plan to conduct clinical investigations to test this hypothesis in several types of human cancers. At this time, we propose to conduct clinical phase I studies to establish the maximum tolerable doses of radiation that can be delivered to patients with T3 and T4 carcinoma of the nasopharynx, stage B2 and C carcinoma of the prostate, and incompletely resected T1-T4, N0-N2 non-small cell lung carcinoma. To do this, we shall use new approaches of three dimensional (3D) conformal treatment planning and new 3D multi- segment treatment delivery systems as tools for dose escalation. Furthermore, the data obtained in these studies will be used to establish tumor control probabilities (TCP's) and normal tissue complication probabilities (NTCP's) for the tumor sites, stages and treatment techniques under study in this Research Project. These data, together with complete dose volume information for each patient, will be of importance for research in treatment plan evaluation, treatment plan optimization, and tumor control and complication analyses. Once these initial studies have been completed, phase III trials in properly selected patients will be designed to test the basic hypothesis and to determine whether improved conformality by 3D techniques at traditional radiation dose levels is sufficient to achieve optimal local tumor control, or whether increased doses are also required to improve local control and outcome. These studies are essential since it is unknown whether increasing radiation doses will overcome inherent tumor radioresistance and whether such treatment will lead to improved local control over that currently available with conventional radiotherapy techniques. Moreover, they are necessary to demonstrate the principles of increasing cancer cure with high precision radiotherapy.